The present invention relates to a repeatedly operable timer where previously selected time information is re-established upon the lapse of the selected time information and such operation is repeated until any key or switch is manually operated.
A prior art timer is adapted to store preselectable time information once and, when the remaining time information reaches zero, come to a dead stop. If it was desirable to measure same period of time repeatedly, it was therefore necessary to re-start the time keeping performance immediately after the preselected time period has passed. Practically, this is completely impossible. A repeatedly operable timer is most desirable from an economy standpoint in the case where a charge depends primarily on time like parking charges and telephone charges.
Accordingly, it is an object of the present invention to provide a repeatedly operable timer which measures a time period repeatedly.
In its broadest aspect, the repeatedly operable timer of the present invention is provided with means for loading preselected time information into the timer repeatedly whenever the preselected time information has passed. In one preferred form of the present invention, the repeatedly operable timer includes an input unit for the introduction of preselectable time information, a first and a second storages for storing same preselectable time information introduced, a subtractor which effects subtraction of the time information stored in the first storage at a given interval, a detector which detects if the time information left in the first storage reaches zero as a result of the subtraction, and a control which permits the time information in the second storage to be transferred into the first storage in response to the output of the zero detector.